The subject matter disclosed herein relates to a rotor balancing apparatus and, more particularly, to a rotor balancing apparatus for a rotary element
In helicopters and other rotorcrafts, rotors rotate about certain axis to provide lift and thrust forces. For example, the main rotor of a helicopter generally includes a number of blades emanating from a hub that rotates about the vertical axis. The blades interact with the air surrounding the helicopter to generate aerodynamic lift forces that provide lift for the helicopter. With this construction, any mass unbalance on the rotor or the blades can lead to vibration in the cabin of the helicopter, which can cause passengers to be uncomfortable. As such, correcting the mass unbalance of a helicopter rotor or blades is an important goal in helicopter design and manufacturing
The above-noted mass unbalance can be caused by imperfect blade and hub manufacturing repeatability, blade paint and surface material erosion or damage, unequal moisture retention and regular or unscheduled maintenance. Currently, helicopters often use fixed, manually installed balance weights on the rotor hub to compensate for the mass unbalance. Adjustments of these weights are performed using various monitoring systems that collect vibration data, which can be used to determine where mass unbalances are located. In some cases, these systems collect the vibration data in the fuselage and compute required balance weights that should be installed to minimize the vibrations. Typically, 0-5 pounds of weights are added to hub arms as a result of this process.
It has been found, however, that the systems and processes for adding the weights can be expensive and may lead to certain errors, such as human errors associated with manual weight installations. Also, while the fixed balance weights may be suitable for ground runs where the vibration data was collected, optimal balance weights are known to change in-flight due to the unique flying characteristics of each rotor blade.